The invention relates to intravascular catheters that can be used to control patient temperature.
Intravascular catheters have been introduced for controlling patient temperature. Typically, a coolant such as saline is circulated through an intravascular heat exchange catheter, which is positioned in the patient""s bloodstream, to cool or heat the blood as appropriate for the patient""s condition. The coolant is warmed or cooled by a computer-controlled heat exchanger that is external to the patient and that is in fluid communication with the catheter.
For example, intravascular heat exchange catheters can be used to combat potentially harmful fever in patients suffering from neurological and cardiac conditions such as stroke, subarachnoid hemorrhage, intracerebral hemorrhage, cardiac arrest, and acute myocardial infarction, or to induce therapeutic hypothermia in such patients. Further, such catheters can be used to rewarm patients after, e.g., cardiac surgery or for other reasons. Intravascular catheters afford advantages over external methods of cooling and warming, including more precise temperature control and more convenience on the part of medical personnel.
The following U.S. patents, all of which are incorporated herein by reference, disclose various intravascular catheters/systems/methods: U.S. Pat. Nos. 6,419,643, 6,416,533, 6,409,747, 6,405,080, 6,393,320, 6,368,304, 6,338,727, 6,299,599, 6,290,717, 6,287,326, 6,165,207, 6,149,670, 6,146,411, 6,126,684, 6,306,161, 6,264,679, 6,231,594, 6,149,676, 6,149,673, 6,110,168, 5,989,238, 5,879,329, 5,837,003, 6,383,210, 6,379,378, 6,364,899, 6,325,818, 6,312,452, 6,261,312, 6,254,626, 6,251,130, 6,251,129, 6,245,095, 6,238,428, 6,235,048, 6,231,595, 6,224,624, 6,149,677, 6,096,068, 6,042,559.
Because it is sometimes desirable that a patient""s temperature be changed to a desired value as rapidly as possible, the present invention recognizes the need to provide an intravascular heat exchange that has a relatively large cooling and/or rewarming capacity.
A heat exchange catheter includes a body, a coolant supply lumen in the body, and a coolant return lumen in the body. A heat exchange element communicates with the lumens and is configured for placement within a blood vessel of a patient such that blood can flow past the heat exchange element. Coolant is circulated through the body in a closed loop. In one embodiment, the heat exchange element includes plural longitudinally-spaced links at least when coolant flows through the catheter, with each link facing its adjacent links and longitudinally overlapping its adjacent links to establish what can be considered an xe2x80x9ceagle clawxe2x80x9d configuration.
In a preferred non-limiting embodiment the links are longitudinally in sequence with each other. Each preferred link includes a straight hollow top oriented parallel to a long axis of the catheter. Also, each preferred link includes two hollow legs made integrally with the respective top and extending downwardly from opposite ends of the top. The legs may be connected to or made integrally with respective connector segments, with each connector segment connecting a leg of one link with a leg of another link.
At least a portion of each link preferably overlaps respective portions of adjacent links, and is spaced transversely therefrom, such that a longitudinal space is established between every other link.
In another aspect, a heat exchange catheter can include means for conveying coolant. Heat transfer means are connected to the means for conveying coolant. The heat transfer means include non-straight, non-helical link means for exchanging heat with a person""s blood.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: